DULONG, (PIERRE) & (ALEXIS) PETIT. - THE "LAW OF DULONG AND PETIT" ANNOUNCED.

Recherches Sur la Mesure des Températures et sur les Lois de la communication de la chaleur. Introduction. (+) Suite des Recherches sur la Mesure des Témperatures..... Seconde Partie. Des Lois du Refroidissement. (+) Suite Des Recherches sur la Mesure des Températures, et sur les Lois de la communication de la chaleur. Du Refroidissement dans l'air et dans les gas. (3 Papers).

Paris, Crochard, 1817. Contemp. hcalf, richly gilt spines. Light wear at top of spine. Minor scratches to edges. Small stamps on verso of titlepages and verso of plates. In: "Annales de Chimie et de Physique, Par MM. Gay-Lussac et Arago.", tome 7, 2e Series. 448 pp. a. 2 engraved plates. (the entire volume offered). Dulong & Petit-papers: pp. 113-154, pp. 225-264, pp. 337-367. Clean and fine.

First edition of these 3 groundbreaking papers with the first appearance in print of THE LAW OF THE CONSTANCY OF ATOMIC HEAT, i.e. the specific heat multiplied by the atomic weight. The insight had far reaching implications as it showed a new way to Dalton's atomic theory.

"In 1815 Dulong's famous collaboration with the mathematical physicist Alexis Therese Petit began; it produced three importent memoirs on heat." (the papers offered here). The 2 first was awarded the price of the Academy in 1818 and was leading up to the last paper in which they formulted the "Law of the Constancy of product of atomic weight and specific heat"
"They (Dulang and Petit) were concerned with the specific heats of elements; but if these elements really existed as atoms, it seemed possible that there might be a connection between trhe weight of the atom and the amount of heat aquired to raise the temperature of a given weight of that element by a certain amount." (DSB). -

"One of his (Dulong) most importent researches was made in collaboration with Alexis Thérese Petit (1791-1820), with whom he announced the law that the product of atomic weight and specific heat is constant (1819). It rendered a distinct service in fixing atomic weights, especially when these were in question, and enabled Berzelius and later Cannizzaro to arrive at correct atomic weights and the correct number of atoms in molecules." (Leicester & Klickstein, A source Book in Chemistry 1400-1900, p. 273). - Parkinson, Breakthroughs (1819).

Order-nr.: 43914